1. Field of the Invention:
The present invention relates to a road retreatment plant and, more particularly, to such a plant embodying a construction and arrangement of parts to enable reconditioning of a roadway comprised of a plurality of layers to a total depth of up to 33 centimeters and mixing the recovered aggregate material with a binder comprised of cement or an emulation of bituminous to form a replacement roadway.
2. Description of the Prior Art:
There exists today a need for increasing the strength of roadways to accommodate a very substantial growth of roadway traffic, particularly heavy vehicles, such as trucks, and to meet the requirements for establishing a roadway network that is unaffected by sub-freezing temperatures, i.e., frost free. Heretofore, solutions proposed for increasing the strength of the roadway merely extended the useable life of the roadway by a few years without insuring a suitable increase to the strength of the roadway bed. In order to overcome the short comings, research has been undertaken to develop a retreatment plant capable of retreating a roadway bed to effectively increase the strength of the road bed for a very long period of time and at a limited cost which is substantially lower in the majority of instances than the cost of only roadway maintenance work.
In French Pat. No. 85 12 724 there is disclosed a device intended to move over a roadway to be reconditioned. The device spreads a layer of binder, in particular cement and water, on the worn roadway then excavates the binder and roadway material to a predetermined depth which is subdivided and crushed to form aggregate before the entire mixture is mixed. After mixing is completed, the mixture of aggregate and binder is spread onto the excavation sight to form a replacement roadway. The device consists of a self propelled vehicle having thereon beginning at the forward portion of the vehicle, a sequential arrangement of a cement batcher, a excavating unit situated in a segregated chamber to break-up the roadway material which is to be treated, a sizing grid, and a mixer unit. Despite obvious advantages of such a machine, the machine did not operate in a manner to produce the results which were expected and desired. Highly efficient mixing of the aggregate and binder is necessary and essential for the production of a reconditioned road bed in order to impart a homogenous, stable, and above all a road bed impervious to frost.